Smoke and spark preventing device.



- Patented Aug. I9, |902. w. s. HUGHES. SMUKE AND SPARK PREVENTING DEVICE.

(Application led Jan. 7, 1902.)

(No Model.)

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Nrrnn STATES l'AT-ENT OFFICE.

WILLIAM S. HUGHES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO EDWARD A. WILLARD, OF NEW YORK, N. Y.

SMOKE AND SPARK PREVENTING DEVICE.

SPECIFICATION forming part of Letters Patent No. 707,332, dated August 19, 1902.

Application filed January 7, 1902. Serial No. 88,713. (No model.)

T0 @ZZ whom, it may concern:

Be it known that I, WILLIAM S. HUGHES, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a certain new and useful Improvement in Smoke and Spark .Preventing Devices, of which the following is a specification. v

My invention relates to a new and useful improvement in smoke and spark preventing devices, and has for its object to provide an improved device of this description which will cause a more perfect combustion of coal and other gaseous substance used for fuel in locomotives and other'steam-boilers orin any furnace where smoke and other obnoxious gases are required to be done away with.

With these ends in view this invention consists in the details of construction and combination of elements hereinafter set forth and then specifically designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same, the construction and operation will now be described in detail, referring to the accompanying drawings, forming a part of this speciication,"in

which- Figure 1 is a longitudinal vertical section of a lire-box and a portion of the boiler, showing my device applied thereto; Fig. 2, a vertical cross-section through the forward end of the fire-box looking toward the rear.

A represents an arched struct ure extending from one side sheet to the other of the fireboX and arranged at an angle in the same, the lower end of the structure extending from the rear of the grate-bars upward toward the forward upper corner of the fire-box, the upper end of the structure being preferably higher than the door of the furnace. This structure is composed of the front and rear walls'B and C, respectively, and 'these Walls are composed of fire-brick or any refractory material which will stand a high degree of heat. These walls do not touch one another, but are closer together at the lower end than at the upper, so as to leave a tapering passage D in between the same extending the full width of the fire-box. At the upper end of the structure is formed an opening E, formed through the forward wall B, and this opening E also extends the full width of the fireboX and is curved to conform with the arch of the structure A. The lower or smaller end of the passage D is open through the bed of the furnace for the purpose of allowing cool fresh air to enter through the reduced end of the passage D. This lower openingis adapted to be controlled by a damper F, connected with suitable mechanism which can be operated by the engineer for opening or closing the same to admit more or less air to the passage. The cool fresh air entering into the passage D will be heated as it passes up through the same, and therefore will be eX- panded; but the passage D by widening toward the top will besuicient to accommodate this expansion so as not to cause a back pressure to retard the inflow of the air, and the opening E will be of suicient size to al- .low the -air to pass into the re-box without any resistance thereto.

J represents the furnace-door, which has an opening formed therethrough, and upon the inner face of the door is secured a downwardlyinclined hood or baffle-plate J', which will direct any air entering through the opening in Vthe door J downward in the direction of thev fire-bed.

K is a door or damper hinged to the door J for thepurpose of regulating the iniow of the air through the opening. The door J is hinged at the point J 2, so that said door and hood J, may be swung entirely out of the way when desired to feed the furnace. I am aware that this'form of door has been used in other furnaces and is not new; but I wish to use it incombination with my other improvements for" the purpose set forth.

It will be seen that by reason of the inclination of the structure A and the opening E being through the forward wallr B the highlyheated airwhich will be drawn through the opening E will be ejected downward and will come in contact with the unconsumed gases and fine coal-dust which tend to pass over the top of the arch on their way to the ues or tubes. At the same time a current of air will low inward through the furnace-door and roo will also be projected downward by means of the hood or baflie-plate J. This discharging of the two currents of air slightly downward in the direction of the lire-bed against the draft will cause an eddy or whirl which will have the effect of baffling and giving the hot air more time to form perfect combustion, which burns up the coal-dust and obnoxious gases which would otherwise be carried through the flues and through the smokestack, and this action will also have the effect of preventing the escape of sparks, because of the fact that it counteracts the effect of the draft from underneath the tirebed which tends to cause the sparks to raise and ju mpabove the nre-bed, the lighter of the sparks escaping to the fines; but these down` wardly-projecting currents of air will prevent the raising of the sparks or prevent them from escaping over the arch into the fines.

For the purpose of making the combustion still more complete I provide in the arched structure A a series of nozzles G, which are secured to the front wall B and extend through the passage D and have a tapering opening formed therethrough. These nozzles G only extend to the rear wall C and are not connected to the same, but open into an enlarged opening H, formed through the rear wall C, and the effect of these nozzles will be that a quantity of highly-heated iiame will rush through the same and be projected to the rear of the structure A through the opening H in the rear wall C. This will have the effeet in passing out of the nozzles to draw with it a quantity of air from the air-passage D, which will be discharged at the rear of the structure A and will provide a combustion at the rear of any coal dust or ashes which may have passed over the arch and escape the influence of the heated air issuing from the opening E. Another purpose of the nozzles G is to more thoroughly heat the air passing through the passage D, which air will come in contact with the nozzles G, which will greatly aid in heating the air on account of the iiame passing through the same. These nozzles, and particularly the ones in the lower part of the structure A, form another very important function, which consists in keeping the lower part of the rear wall ortube-sheet of the firebox at an equal temperature with the other parts of the tire-box by allowing the flame to pass through the nozzles and come in contact with the tube-sheet,\vhich would otherwise, on account of the intervention of the arch, be a non-heating surface and would thus cause an unequal expansion to that part of the sheet, which would be attended by injurious results to the tubes and the sheet itself.

As will be seen, on account of the introduction of the arch A in the fire-box a pocket will be formed between the rear wall C of the arch and the rear wall of the fire-box, and in this pocket dust will accumulate either from the cleaning of the tubes of the boiler or from particles dropping into the same after passing over the arch. For the purpose of removing this accumulation from time to time I provide at the lower end of the pocket, at the junction of the rear wall C of the arch with the rear wall of the fire-box, a steam-pipe I, which extends the full width of the fire-box and is connected with a suitable supply of steam and will be provided with a valve under the control of the operator. The upper side of this pipe I has a series of holes t' formed therethrough, which will project the steam upward. Thus when it is desired to remove any accumulation of dust the operator will allow a small amount of steam to pass through the pipe I, which in issuing from the holes z' will blow the dust upward, and thus effectually remove the same. This would only have to be used occasionally and is not used in any way to promote combustion.

I am well aware that numerous devices in brick arches have been invented and experimented with which, with the necessary changes which had to be made in fire-boxes, were very expensive and in some devices were ruinous to the fire-box, and, further, were very imperfect in producing combustion. The cause of this has been that the fact of the natural effect of heating air has not been taken into consideration. It is well known that air taken at atmospheric temperature expands according to the degree of heat to which it is subjected, and no provision for this expansion was made in the passage leading from the inlet to the outlet, and in consequence as the air passing through the passage became heated and expanded a much less supply of pure air would pass through the inlet on account of the expanded air meeting resistance, which would cause a back pressure. In my invention I provide ample room in the passage for the increasing of the expansion of the air when it has reached the upper end of the arch. This feature, taken in connection with the nozzles G and the blowpipe I, forms my invention, the advantage of which is that it will effectually do IOO IIO

away with the throwing of sparks and the boiler will make more steam and use less fuel, because the fuel is burned in the iirebox, where it should be, instead of being thrown partly out of the stack.

The throwing of sparks and smoke from the stack is an annoyance which is particularly noticeable in locomotives. In this case it is usually caused by the necessary force of the exhaust which is used to stimulate the fire, so that the boiler will generate the required amount of steam to do the work. By using my improved smoke and spark preventing device the foregoing disadvantage will be avoided and the boiler will make more steam and the engine run more freely by enabling an increase in the size of the exhaust-nozzle to be used.

Of course I do not wish to be limited to the exact construction here shown,\as slight modications could be made without departing from the spirit of my invention.

Having thus fully described my invention, what I claim as new and useful isl. In a device of the character described, an arched structure arranged within the rebox and extending entirely across the same, said structure composed of a front and rear wall commencing at the lower rear corner of the iire-box and extending upward and forward and terminating at a point above the line of the furnacedoor,said walls so arranged as to form a gradually-widening passage in between the Same, the narrowest portion be-` ing at the inlet and the widest portion being at the upper end, the forward wall being provided at the upper end with an opening, a series of nozzles secured to the forward wall and extending through the passage in between the walls, said nozzles being provided with openings therethrough, the rear wall having openings opposite the nozzles but of larger diameter than the same, a damper or valve arranged at the inlet end ofthe passage for regulating the supply of air, an opening formed through the furnace-door, a hood secured to the inner face of the door and projecting inward in a downwardly-inclined vdirection, substantially as and for the purpose` speciiied.

2. In a device of the character described, an arched structure arising from the lower rear corner of the re-box and inclined forward and terminating at a point above the furnace-door, a tapering air-passage formed in the structu re, said passage opening through the bed of the hre-box, the structure provided with an opening at its upper end so arranged as to discharge the air slightly downward, a series of nozzles having openings formed longitudinally through the same secured to the forward portion of the structure and extending through the passage, the rearward portion of the structure `being provided with openings registering with the nozzles but of larger diameter than the same, an opening formed through the furnace-door, a baffleplate or hood arranged upon the interior for directing the air passing through the opening downward toward the fire-bed, a damper or supplementary door for regulating the inow of air through such opening, a steampipe arranged in the angle between the rear of therstructure and the rear iire-bed wall, said steam-pipe having openings formed in the upper portion thereof so as to eject the steam upward, as and for the purpose specied.

In testimony whereof I have hereunto affixed my signature in the presence of two subscribing witnesses.

WILLIAM S. HUGHES.

Witnesses:

H. B. HALLocK, L. W. MORRISON. 

